Entropy generation analysis of radiative nanofluid flow inside a permeable chamber with heat generating source

Purpose This study aims to investigate entropy generation in radiative heat and mass transfer of nanofluids within a square cavity, considering the combined effects of thermophoresis, Brownian motion and chemical reactions, to optimize thermal performance while minimizing entropy generation. Design/methodology/approach The coupled nonlinear partial differential equations governing nanofluid flow, temperature, concentration and entropy generation are formulated based on Buongiorno’s model and solved numerically using the finite element method. The study systematically examines the impacts of thermophoresis, Brownian motion and chemical reaction parameters on nanoparticle distribution, thermal and concentration boundary layers and entropy generation under varying thermal radiation conditions. Findings Thermophoresis and Brownian motion significantly influence nanoparticle distribution and boundary layer characteristics, affecting entropy generation. Chemical reactions modulate mass transfer rates and entropy production. Increasing the thermal radiation parameter enhances temperature distribution while reducing total entropy generation within the cavity. Increasing the Rayleigh number (Ra) from 103 to 5 × 103 enhances heat transfer by about 18%, while higher radiation (R) and porosity (K1) parameters reduce entropy generation by roughly 12% and 15%, respectively. Originality/value This work provides insights into the optimization of nanofluid-based thermal systems by demonstrating how nanoparticle dynamics and chemical reactions interact with thermal radiation to minimize entropy generation and improve heat and mass transfer performance. Also, the integrated analysis of Buongiorno’s nanofluid model, Brownian motion, thermophoresis, entropy generation and porous medium is not previously reported in the open literature.